Indexing and Reorganization in Parallel Database Systems

并行数据库系统中的索引和重组本研究项目的目标是设计、分析和模拟并行数据库管理系统（dbms）中在线重组的可重启算法。web应用程序对7/24（一周7天/一天24小时）数据库访问的需求日益增长，这使得这些算法的开发迫在眉睫。电信和基于web的业务（例如，eBay或AOL）中的应用程序需要非常大的、高可用性的数据库。这些数据库现在或很快将由并行dbms管理（即，工作站集群上的dbms，每个dbms管理自己的磁盘集合，通过局域网（lan）连接），因此在数据库的逻辑和物理更改以及意外增长面前保持可用性的并行算法非常重要。项目中部署的方法包括对显式日志操作的描述，以确保一致性，并在并行系统的任何节点上面对可能的系统故障时保持增量改进。与工业界的合作是该项目的一部分。孙晓薇女士是该项目的博士生，她已经在Clustra公司完成了实习，该公司的产品是为高可用性而设计的并行复制DBMS。她还在多伦多IBM公司实习，为IBM的DBMS DB2进行在线重组。与行业的密切联系以及当前在线重组问题的重要性将加强该项目成果的影响，包括预期的技术转让。http://www.ccs.neu.edu/home/salzberg/nsfproj2000.html

Indexing and Reorganization in Parallel Database SystemsThe goal of this research project is to design, analyze and simulate restartable algorithms for on-line reorganization in parallel database management systems (DBMSs). The growing need for 7/24 (7 days a week/24 hours a day) database access for web applications makes development of these algorithms urgent. Applications such as those found in telecommunications and web-based businesses (for example, eBay or AOL) require very large highly available databases. These are or will soon be managed by parallel DBMSs (i.e., DBMSs on clusters of workstations, each managing its own collections of disks, connected by Local Area Networks (LANs)), so parallel algorithms to maintain availability in the face of logical and physical changes to the database as well as unexpected growth are important. The approach deployed in the project includes the description of explicit logging operations to assure consistency and preserve incremental improvements in the face of possible system failures at any node of the parallel system. Collaboration with industry is part of the project. Ms. Xiaowei Sun, a supported Ph.D. student on the project, has completed an internship at Clustra, Inc., whose product is a parallel replicated DBMS designed for high availability. She is also doing an internship with IBM Toronto on online reorganization for IBM's DBMS, DB2. The close contact with industry and the current importance of the problem of online reorganization will strengthen the impact of this project's results, including the expected technology transfer.http://www.ccs.neu.edu/home/salzberg/nsfproj2000.html